Moissanite vs Lab Grown Diamond: Which Is Best?

Moissanite vs lab grown diamond: which is best? The short answer is that a lab grown diamond is a real diamond (pure carbon), while moissanite is a different gemstone (silicon carbide) that looks similar but isn’t a diamond. Moissanite is cheaper and has extra “fire,” but a lab grown diamond gives you the genuine diamond look, hardness and certification that most people want, usually for a still-affordable price. Here’s the full, honest moissanite vs lab grown diamond comparison from a UK jeweller’s point of view.

Moissanite vs lab grown diamond: what is each one?

• Lab grown diamond: a genuine diamond, grown in a lab from pure carbon. Chemically and optically identical to a mined diamond. (More on this in Are lab grown diamonds real?)

• Moissanite: a lab-created gemstone made of silicon carbide. It’s a beautiful, durable diamond alternative — but it is not a diamond.

This is the heart of the difference: one is a diamond, the other is a diamond simulant.

Side-by-side comparison

Material — Lab grown diamond: Pure carbon (real diamond); Moissanite: Silicon carbide (diamond simulant).

Is it a diamond? — Lab grown diamond: Yes; Moissanite: No.

Hardness (Mohs) — Lab grown diamond: 10 (hardest); Moissanite: 9.25 (very hard).

Sparkle — Lab grown diamond: Classic white diamond brilliance; Moissanite: More “fire” / rainbow flashes.

Certified & graded as a diamond — Lab grown diamond: Yes (4Cs); Moissanite: Graded separately.

Relative price — Lab grown diamond: Higher than moissanite, far below mined; Moissanite: Lowest.

Best for — Lab grown diamond: A genuine diamond look & feel; Moissanite: Maximum sparkle on the smallest budget.

Sparkle: a real difference you can see

Moissanite is known for its high level of “fire”, creating vibrant rainbow flashes of colour, especially in larger stones. While many people enjoy this distinctive sparkle, others prefer the more traditional appearance of a diamond. Lab-grown diamonds offer exactly the same beauty, brilliance and sparkle as mined diamonds, making them the ideal choice for those who want the authentic diamond look at a more accessible price.

Durability

Both stones are durable enough for everyday wear. A lab-grown diamond is the hardest known gemstone, scoring 10 on the Mohs hardness scale, while moissanite scores around 9.25. In practical terms, both are highly resistant to scratching and suitable for daily wear, although diamond remains the benchmark for durability.

Price: the honest picture

Both moissanite and lab-grown diamonds have become popular alternatives to mined diamonds, offering exceptional beauty at a more accessible price point. The key difference is that a lab-grown diamond is a real diamond with the same chemical, physical and optical properties as a mined diamond, while moissanite is a separate gemstone with its own unique look and characteristics.

Which should you choose?

Choose a lab-grown diamond if you want a real, certified diamond with the same chemical, physical and optical properties as a mined diamond. It offers the timeless beauty, durability and prestige of a natural diamond at a far more accessible price point.

Choose moissanite if keeping costs as low as possible is your top priority and you’re happy with a gemstone that offers a different look and light performance to a diamond.

At Selene Origins, we chose to specialise exclusively in lab grown diamonds, certified diamonds (F/G colour, SI clarity) set in 14k gold vermeil or platinum plating over solid sterling silver. We think it’s the best balance of authenticity, beauty and value. You can browse our lab grown diamond rings here, or explore a bespoke design.

Frequently asked questions

Is moissanite a diamond? No. Moissanite is silicon carbide, a diamond simulant. A lab grown diamond is a genuine diamond made of carbon.

Is moissanite or lab diamond better? Neither is universally “better”. A lab-grown diamond is a real, certified diamond with the same properties as a mined diamond, while moissanite is an alternative gemstone that offers a different style of sparkle. The right choice depends on what matters most to you.

Can you tell moissanite from a lab grown diamond? Up close, moissanite often shows more colourful flashes. Definitive identification needs gemological testing, but the sparkle character differs.

Do lab grown diamonds and moissanite last? Both are very durable. Lab grown diamonds rate 10 on the Mohs hardness scale; moissanite rates 9.25 — both suitable for everyday wear.